Video and audio source material editing systems employing digital techniques have been introduced over the last several years. One example is the Avid/1 Media Composer from Avid Technology, Inc., of Burlington, Mass. This media composer receives, digitizes, stores and edits video and audio source material. After the source material is digitized and stored, a computer such as an Apple Macintosh based computer manipulates the stored digital material and a pair of CRT monitors are used for displaying manipulated material and control information to allow editing to be performed. Later versions of the media composer included compression techniques to permit the display of full motion video from the digitized source material. Compression was achieved using a JPEG chip from C-Cube of Milpitas, Calif. That data compression is described more fully in U.S. Pat. No. 5,513,375, issued Apr. 30, 1996, which matured from U.S. Ser. No. 07/807,269 filed Dec. 13, 1991, now U.S. Pat. No. 5,513,375, and entitled Buffer and Frame Indexing. The teachings of this application are incorporated herein by reference. Although previous media composers could achieve full motion video from digitized sources, the compression degraded image quality below desirable levels. Further, the media composer lacked features which enhance the editing process.